DE10392375T5 - Separation process for platinum group elements - Google Patents

Abstract

A method of separating platinum group elements, comprising:
a step (A) for treating a material containing selenium / tellurium and platinum group elements with alkali,
a selenium / tellurium leaching step (B), and
a step (C) for separating a platinum group element-containing leach residue and a selenium / tellurium caustic.

Description

technical area

The The present invention relates to a treatment method, which the effective separation of selenium, tellurium and platinum group elements allows a material containing selenium / tellurium and platinum group elements. In addition, concerns the present invention also provides a separation process which provides the effective precipitation and separating residual gold from a solution, the platinum group elements contains which was obtained by treating the material, selenium / tellurium and platinum group elements. A separation process according to the invention is perfect for one Process for the separation and recovery of selenium, tellurium and Platinum group elements from the reduction slag obtained becomes by reduction treatment of a liquid after the gold extraction in a process for recovering precious metals from a Mud of copper electrolysis.

According to the invention a selenium / tellurium mixture is a mixture of selenium and tellurium and describes for example, precipitation, which is obtained by neutralizing the filtrate obtained is by filtering the residue, of the elements of the platinum group contains, from a liquid the gold extraction produced from a decuperated sludge. About that addition, a material that contains selenium / tellurium and elements of Contains platinum group, a material that is at least one of selenium and tellurium together containing elements of the platinum group and the term selenium / tellurium means Selenium and / or tellurium.

at the copper electrolysis process, during the smelting of Copper is carried out are also impurities that are insoluble in the electrolyte, formed as residual by-product. This by-product contains considerable amounts on platinum group elements such as Pt, Rh, Ir and Ru, as well as selenium, Tellurium, gold, silver and copper. There have already been numerous procedures proposed for the separation and recovery of these metals. For example, platinum group elements become out of the mud the silver anode that during a refining stage for Silver is formed and released from the sludge, with the addition of nitric acid to this Sludge is formed, recovered, the metal components, which are different from gold, are leached out and then the Residue is reduced. Conventionally, to dissolve this slurry, a resolution in Aqua regia, a resolution in hydrochloric acid and hydrogen peroxide or a solution in hydrochloric acid below performed a chlorine gas stream.

however form in the case of materials containing selenium / tellurium and elements of Containing platinum group, wherein selenium and / or tellurium together with the elements of the platinum group are present when applying the reduction to form a precipitate, the elements of the platinum group compounds with the selenium / tellurium, difficult in aqua regia or hydrochloric acid and hydrogen peroxide dissolve which means that the separation and recovery becomes impossible. Hydrogen peroxide decomposes on the surface of selenides and can therefore not act as an oxidizer. It also became a procedure for roasting these compounds to effect a separation of selenium oxide and tellurium oxide in the vapor state, although the toxicity of this Materials leads to significant environmental problems.

A method of separating platinum group elements and selenium / tellurium contained in a liquid after extraction of gold from a slurry obtained in the electrolysis, wherein the concentration of chlorine ions in the liquid is not more than 1 5 mol / L is maintained while sulfur dioxide gas at a concentration of 8 to 12% is bubbled through the liquid at a temperature of 60 to 90 ° C, whereby the platinum group elements are reduced and precipitated (Japanese Unexamined Patent Application, First Publication No 2001-316735), and a process for recovering the extraction residue produced in the solvent extraction of gold and platinum group elements from a hydrochloric acid leach obtained from a slurry of copper electrolysis and then introducing sulfur dioxide into this post-extraction liquid , for the reduction and precipitation of selenium / tellurium (Japanese it patent no. 3 087 758 and Japanese Unexamined Patent Application, First Publication No. 2001-207223) are already known.

However, in these methods, the control is difficult because a large number of parameters must be controlled during the reduction of selenium, such as the concentration of hydrochloric acid, the temperature and the concentration of sulfur dioxide gas and the sulfur dioxide gas flow rate, resulting in a reduction of the yield for the elements of the platinum group and selenium / tellurium leads. Moreover, carrying out the steps in the two-stage reduction treatment using sulfur dioxide is extremely difficult, and some incorporation of selenium tellurium or platinum group elements into the precipitates is unavoidable, which means that separation based solely on reduction by sulfur dioxide is not satisfactory is. In addition, the separation of platinum group elements and selenium / tellurium using solvent extraction is a costly process and the recovery treatment required following extraction is both complex and time consuming.

It also a procedure was suggested, in which instead of the treatment with hydrochloric acid and sulfur dioxide the sludge of the copper electrolysis of a leaching treatment in a sulfuric acid solution with pressurized, oxygen-enriched gas (Japanese unaudited Patent Application, First Publication No. Hei 5-311258) and a method in which, following the leaching of the sludge of the copper electrolysis in a sulfuric acid solution oxygen-enriched gas, the leaching desilvered by treatment with chlorine ions and a sodium thiosulphate solution and then Copper is added (Japanese Unexamined Patent Application, First Publication, No. Hei 5-311264) are also proposed, however These types of process, the copper under conditions of under Use pressurized oxygen-enriched gas, difficult to perform and very expensive and therefore not practicable.

Other known methods include a method in which an oxidizing agent is used to oxidize metallic selenium and the resulting Product will follow neutralized with an alkali metal carbonate or hydroxide, wherein a Alkalimetallselenat is formed (Japanese Unexamined Patent Application, First Publication No. Sho 60-176908), a method in which a Selenium-containing material reacted with an alkali metal carbonate is going to be a watery slurry to form and this slurry subsequently in an oxidizing atmosphere is fired under formation of pellets, which are subsequently with Leached water (Japanese unexamined patent application, first Publication No. Sho 56-5306), a method in which a tellurium containing sludge is dissolved in a mineral acid in the presence of an oxidizing agent, subsequently an alkali to the solution to precipitation and separation of copper is added and the remaining solution then for precipitation of tellurium is neutralized (Japanese Unexamined Patent Application, First Publication No. Sho 56-84428) and a method in which a raw material such as the mud of the Copper electrolysis, with a strong acid such as hydrochloric acid and also with an oxidizing agent, such as chlorine, if the raw material Contains compounds, followed by butylcarbitol as solvent for extraction of tellurium (Japanese Unexamined Patent Application, First Publication No. 2000-239753). However, all these methods require a big Number of stages and the recovery rates for selenium / tellurium are also low.

The present invention solves the above problems associated with the usual technology and has as its object the provision of a separation process that allows Selenium / tellurium and platinum group elements are light and effective a material, selenium / tellurium and platinum group elements contains.

Furthermore is, as described above, in a separation process, the on the evaporation by roasting based on selenium, a big one Proportion of selenium hexavalent, which is a big burden for the subsequent treatment represents the wastewater.

Accordingly is a method for the resolution of a. By the present invention Materials provided that include both platinum group elements also contains selenium, and that is capable of solving the above problems which with usual procedures by providing a resolution process that is effective Leaching of selenium allows whereby a separation of elements of the platinum group is possible.

In addition, As described above, the implementation of the stages of a two-stage Reduction treatment using sulfur dioxide extremely difficult and some incorporation of selenium or platinum group elements into the precipitates let yourself not avoid, which means that the separation, which only based on the reduction by sulfur dioxide, unsatisfactory is. About that In addition, methods in which elements of the platinum group by Solvent extraction removed and then separated from selenium and / or tellurium, expensive and the following recovery treatment required following extraction is time consuming. About that In addition, each of these methods describes the separation of elements the platinum group and selenium, which are already present within a solution and do not affect the resolution a process precipitation, contains the elements of the platinum group and selenium and the like.

each the above-described method for the recovery of selenium and Tellurium is a process in which selenium and / or tellurium oxidizes and solved be possible, however none of these methods involves the separation of platinum group elements of selenium in the dissolution stage.

In addition, in the recovery of rhodium, which is one of the elements of the platinum group, rhodium is very easily amenable to oxidation, forming very insoluble rhodium oxide, and therefore it is difficult to dissolve. A procedure For separating rhodium from a slag containing noble metals in which the noble metal-containing slag is heated with a carbon-based reducing agent and the resulting reduction product is treated with a sulfating agent to form rhodium sulfate is known (Japanese Unexamined Patent Application, First Publication No. Hei 5-125461), although this method requires the disadvantage of low yields and the requirement of high temperature treatment.

The The present invention provides a solution treatment method for a material ready containing both platinum group and selenium elements is suitable to solve the above problems of conventional methods, by Providing a method of treatment whereby selenium is selective disbanded and effectively separated from platinum group elements and at the platinum group elements remaining in the solid fraction are subsequently dissolved and recovered become.

In addition to The methods described above include known methods for the production of tellurium, a process in which an anode sludge, while the electrolysis formed for the refining of copper or nickel is subjected to a wet treatment to insoluble silver compounds then separate leached with ammonia or the like to separate the silver, the resulting residue, contains tellurium, is leached with sodium carbonate (Japanese Unexamined Patent Application, First Publication No. 2001-11547), and a method in which the Tellurium-containing filtrate, which during the solvent extraction of gold is reduced to precipitate selenium and the remaining filtrate then under conditions Leaching under pressure with sulfuric acid for leaching to a Decuxed liquor is returned (Establishment of copper precipitate wet treatment technology, Journal of the Mining and Materials Processing Institute of Japan, Vol. 116, page 484, 2000). However, methods for obtaining tellurium from insoluble Silver compounds at low tellurium migration rates. Furthermore is in processes in which the tellurium-containing filtrate for pressure leaching is attributed the rate of leaching unsatisfactory when the tellurium in metallic form, resulting in an undesirable increase in the Procedure to be held volume leads.

The present invention solves these problems with the usual ones Treatment procedures by providing a treatment method, in which a mixture of selenium and tellurium is alloyed with copper, This alloy is subjected to a copper electrolysis to copper to win electrolytically and a selenium and Tellurschlamm to form, and subsequent Leaching of this copper electrolysis sludge for leaching of tellurium and for the separation of selenium, whereby the selenium and the tellurium can be obtained with good effectiveness.

As mentioned above, become impurities in a process for copper electrolysis in copper smelting formed as by-products that are insoluble in the electrolyte. This by-product contains considerable Quantities of gold, silver, copper, platinum group elements such as Pt, Rh and Ru, and Se and Te. There have already been numerous procedures proposed for the separation and extraction of these precious metals. For example For example, a decopper sludge may be subjected to a chlorinating leach where silver and lead are recovered from the resulting sludge and gold from the liquor through a solvent extraction process is won. The remaining liquid contains from this gold extraction Elements of the platinum group as well as Se and Te. This liquid after the gold extraction then becomes a reduction treatment subjected by introducing Sulfur dioxide gas into the system, the initial selenium precipitation, the is first subjected to distillation to high purity selenium to recover and the resulting distillation residue of an alkali melt treatment be subjected to a separation into a selenium-containing liquor and a residue, of the platinum group elements, causing tellurium, this by further introduction of sulfur dioxide gas in the above residual liquid precipitated is subjected to alkali leaching treatment, to a separation into a lye containing selenium / tellurium and a residue, contains elements of the platinum group to effect what selenium and tellurium and the elements of the platinum group from this lye or the residue be won.

In this type of the noble metal recovery system, the gold recovery method usually uses a known solvent extraction method using dibutylcarbitol (DBC) (Japanese Unexamined Patent Application, First Publication No. Sho 57-79135). A method in which an aqueous solution of oxalic acid is added to the extracted solution to reduce and precipitate the gold is also known (Japanese Unexamined Patent Application, First Publication No. 2001-316735). However, in a solvent extraction process using DBC, typically about 0.3% of the solvent remains in the post-extraction liquid. This residual solvent can be removed by distillation, but there is a need for a process for recovering the small amount of gold that is in the solvent and a process for effectively removing that gold during the subsequent stages.

Moreover, a method in which oxalic acid is added to the chlorination leach from a slurry of copper electrolysis and the resulting precipitate is treated with nitric acid and melted by heating (Japanese Examined Patent Application, Second Publication No. Sho 64-3930) and a method in which bis (2-butoxyethyl) ether is mixed with the chlorination liquor of a copper electrolysis sludge, the gold being extracted into the organic phase by the addition of ether, this organic phase being washed with hydrochloric acid and then oxalic acid is used for reduction ( Japanese Patent No. 3 087 758 ) also known. However, processes in which gold is selectively reduced by using oxalic acid have the disadvantage of extremely low reaction rates in cases where the chloride concentration of the chlorinating leaching from the copper electrolysis sludge is high, making the step of reducing gold practically impossible ,

on the other hand are also a process using hydroxylamine hydrochloride, nitrous acid or sulfuric acid as a reducing agent for the extraction of gold from gold containing materials known (Japanese unchecked Patent Application, First Publication No. Hei 2-97626). Furthermore becomes a method in which a complexing agent is produced during the Electroplating a metal material containing palladium and gold and the like, also described (Japanese Unexamined Patent Application, First Publication No. Hei 2-221392). However, that is the amount of gold in the liquid contained after the extraction of gold from a decuperated Mud is obtained, minimal and the amounts of selenium, tellurium and Platinum group elements are higher and accordingly, even if hydroxylamine hydrochloride or an alkylhydroxylamine directly to the liquid joined after the gold extraction will make effective extraction of gold impossible.

According to the invention, an attempt is made to solve the above problems the usual Method for obtaining gold from a material, the selenium / tellurium and contains elements of the platinum group and is formed by Treating the chlorination liquor from a sludge of the copper electrolysis through the provision of a process which effective separation and recovery of gold, which in such a Material included is the selenium / tellurium and platinum group elements contains.

description the invention

Around to solve the above problems the present invention provides a platinum group element separation process which comprises: a step (A) for treating a material that Selenium / tellurium and platinum group elements contain one level with alkali (B) for leaching of selenium / tellurium and a step (C) for separation the alkaline residue containing the elements of the platinum group and the selenium / tellurium lye.

at the above separation method is the treatment step (A) a material containing selenium / tellurium and platinum group elements contains with alkali preferably an alkali fusion process, wherein a Flux (flux), which is a mixture of sodium hydroxide and sodium nitrate contains, too the material joined containing selenium / tellurium and platinum group elements, and the mixture is melted by heating to a temperature exceeds the eutectic temperature of the flux, the step (B) for Leaching of selenium / tellurium is preferably a water leach stage for leaching the resulting melt with water and step (C) for the separation of the lye residue, containing the elements of the platinum group and the selenium / tellurium lye is preferably a step for performing a solid-liquid deposition using a leach with water, causing the mixture in a liquid Fraction containing sodium selenite and a residue containing Contains elements of the platinum group, is disconnected.

at the above separation method is the molar ratio between Sodium hydroxide and the sodium nitrate preferably in one range from 75: 25 to 85: 15.

at In the above separation method, hydrogen peroxide and hydrochloric acid are preferable to the residue, which contains the elements of the platinum group, added to the elements of the platinum group dissolve.

at The above separation method is the selenium / tellurium and elements The platinum group-containing material preferably comprises a precipitate of a extrusion residue a process that remained after solvent extraction, which was applied to gold from the hydrogen chloride to separate a decuperated sludge.

In the above separation method, the above-mentioned material containing selenium / tellurium and platinum group elements is preferably a distillation residue obtained by converting a decomposed sludge into a slurry by adding hydrogen chloride acid and hydrogen peroxide, filtering this slurry to effect separation into a caustic solution containing predominantly silver and a solution containing gold, platinum group, selenium and tellurium, whereupon the liquor liquid conditions are adjusted and solvent extraction for extraction of gold the brine is added, sulfur dioxide is added to the post-extraction liquid to reduce selenium and then tellurium and precipitate, and then the precipitated material containing platinum group elements and selenium is heated to concentrate the platinum group elements while distilling off selenium and is deposited.

at the above separation method is the step (A) for treatment a material containing selenium / tellurium and platinum group elements contains with alkali, and the selenium / tellurium leaching step (B) is preferable carried out simultaneously as Alkaliauslaugverfahren, wherein the selenium / tellurium and Platinum group elements containing material with an alkali Leached at high temperature, with selenium / tellurium in the liquid wander and a solid-liquid separation is subsequently carried out to make the mixture into a solid fraction, the elements of the platinum group contains and a liquid one Fraction containing selenium / tellurium to separate.

at The above separation method is preferably an oxidizing agent to the deposited solid fraction added to the solid-liquid separation under acidic conditions using hydrochloric acid so dissolve the elements of the platinum group.

at the above separation method becomes the selenium / tellurium and elements the platinum group containing material preferably with alkali leached out of a high temperature, causing tellurium in the liquid migrates with the selenium, with a separation of the elements of Platinum group is effected.

at the above separation method becomes the selenium / tellurium and elements preferably using the platinum group-containing material of alkali having a concentration of at least 1 mol / L in one Temperature of at least 60 ° C drained.

at the above separation method hydrochloric acid and either hydrogen peroxide or chlorine gas preferably to the solid Fraction from the solid-liquid separation together, which is carried out after leaching with alkali, so the elements to solve the platinum group.

at The above method includes the elements of the platinum group preferably one or more of rhodium, ruthenium, palladium and Platinum.

at In the above separation process, the material is selenium / tellurium and platinum group elements, preferably an extraction residue method precipitate which after a solvent extraction remained, which was applied to make gold from the hydrogen chloride from a remove decomposed sludge.

at The above separation method is the selenium / tellurium and elements The platinum group-containing material is preferably a filtered precipitation, obtained by conversion of a decuperated sludge in a slurry Addition of hydrochloric acid and hydrogen peroxide, filtering this slurry to effect a separation into a residue, the primary Contains silver and a gold containing elements of the platinum group, selenium and tellurium Lye, subsequent Adjusting the liquid characteristics the brine and application of a solvent extraction, to separate gold from the liquor, addition of sulfur dioxide too the post-extraction liquid, to precipitate either selenium or tellurium and then undergo this precipitation of a Solid-liquid separation.

The above separation method preferably includes:
an alkali smelting process (i) comprising the step of adding a melting agent containing a mixture of sodium hydroxide and sodium nitrate to a residue from the distillation treatment of a material containing selenium / tellurium and platinum group elements, followed by heating to a temperature which is Melting temperature (eutectic) of the mixture, whereby the selenium / tellurium is dissolved, as the above-mentioned step (A) for carrying out the alkali treatment, a step for carrying out a leaching with water, as the above-mentioned step (B) for leaching of selenium And / or tellurium, and further comprising the aforesaid said step (C) for separating the platinum group-containing caustic and the selenium / tellurium caustic, and an alkali leaching process (ii) which comprises the step of leaching a material, selenium / tellurium, and elements The platinum group contains, with alkali at high temperature, as the aforementioned S Step (A) for carrying out an alkali treatment and the above-mentioned selenium / tellurium extracting step (B), and further comprising the above-mentioned step (C) for separating the platinum group-containing alkali residue and the selenium / tellurium alkali ,

At the The above separation method becomes a solution containing selenium / tellurium and Contains elements of the platinum group, preferably subjected to a reduction treatment and the residue, upon subjecting a portion of the resulting reduction precipitate to a Distillation treatment is obtained, then one Subjected to alkali fusion treatment, while the remaining reduction precipitation of a Leaching is subjected to alkali.

at In the above separation method, sulfur dioxide gas becomes an extraction liquid The gold extraction from a precious metal recovery system for a Copper electrolysis sludge introduced, to perform a reduction treatment, and by subjecting the selenium slag that first fails, one distillation, one Separation of highly pure selenium, preferably an alkali melt treatment The tellurium which precipitates next is preferably subjected to alkali leaching treatment is subjected.

at the above separation method is in the leaching of the alkali fusion with Water obtained liquor preferably to the alkali leaching process returned and leaching with alkali together with the material, which contains selenium / tellurium and platinum group elements.

at The above separation method is that in the alkaline leaching method preferably neutralized by addition of sulfuric acid or Hydrochloric acid, whereby selenium / tellurium precipitated becomes.

at hydrochloric acid is preferably used in the above separation method to the lye residue together, in the alkali leaching process and the alkali fusion process is obtained in the presence of an oxidizing agent, so the elements to solve the platinum group.

at In the above separation method, the selenium / tellurium mixture is preferable obtained from the above selenium / tellurium lye and the The selenium / tellurium mixture obtained is then transformed into a copper smelting and refining procedures introduced, to produce an alloy of selenium and tellurium with copper, wherein This alloy is subjected to copper electrolysis to make copper electrolytic with selenium and tellurium in the copper electrolysis sludge accumulate and this copper electrolytic sludge then becomes one Oxidation leaching with sulfuric acid subjected to dissolving the tellurium and from the selenium remaining in the lye residue is separated.

at In the above separation method, a selenium / tellurium mixture is preferably used obtained by adding sulfuric acid or hydrochloric acid to the Selenium / tellurium lye obtained in the above alkali leaching method, whereby the lye is neutralized and the selenium / tellurium mixture is precipitated and the resulting selenium / tellurium mixture is then in a copper refining process introduced, to produce an alloy of selenium and tellurium with copper, these Alloy is subjected to copper electrolysis to make copper electrolytic to win, with selenium and tellurium within the sludge of copper electrolysis accumulated and the sludge of copper electrolysis is then a subjected to oxidative leaching with sulfuric acid, whereby the Tellurium solved and separated from the selenium remaining in the lye residue becomes.

at the above separation method is preferably a selenium / tellurium mixture, which was obtained by adding the selenium / tellurium lye, which from the above Alkaline melting process is derived to the material, the selenium / tellurium and platinum group elements, that in the above Alkali leaching process was used, with an alkali leaching is carried out and subsequently sulfuric acid or hydrochloric acid be added to the resulting liquor, to neutralize the liquor and precipitate the selenium / tellurium mixture and The resulting selenium / tellurium mixture is then placed in a molten copper and refining procedures is used to form an alloy of selenium and tellurium with copper, the alloy of a copper electrolysis for electrowinning is subjected to copper, with selenium and tellurium in the mud the copper electrolysis are accumulated and this mud of the Copper electrolysis then subjected to an oxidative leaching with sulfuric acid which releases the tellurium and separated from the selenium remaining in the lye residue becomes.

at The above separation method is selenium / tellurium and elements The platinum group-containing material preferably comprises a reduction precipitate which is obtained by introducing of sulfur dioxide gas in a liquid after the gold extraction and performing the reduction treatment.

at the above separation method is followed by leaching of tellurium by an oxidizing leaching of the sludge of copper electrolysis preferably brought into contact with metallic copper and the resulting copper telluride is recovered.

In the above separation method, hydrochloric acid is preferably obtained from the platinum group element-containing element Residue is added in the presence of an oxidant, a solid-liquid separation is performed, and hydroxylamine hydrochloride is then added to the filtered solution containing the platinum group elements to selectively reduce and precipitate gold.

at the above separation process, the alkali treatment of the Selenium / tellurium and platinum group elements preferably carried out at high temperature.

at hydrochloric acid is preferably used in the above separation method to the platinum group element obtained residue in the presence of a Added oxidant, a solid-liquid separation is performed and hydroxylamine hydrochloride will follow to the elements of the platinum group containing liquid added to the Selectively reduce and precipitate gold.

at the above separation method becomes a liquid after the gold extraction a noble metal recovery system for copper electrolysis mud preferably used as a material containing selenium / tellurium and elements contains the platinum group, and Sulfur dioxide gas gets into this post-extraction fluid introduced, to perform a reduction treatment, and the distillation residue, which is generated by subjecting the selenium that first fails to distilled to a separation of selenium with high purity and alkali smelting treatment is performed to remove the remaining platinum group-containing residue whereas tellurium is responsible for the further introduction of Sulfur dioxide gas precipitates into the post-extraction liquid, one Alkali leaching is subjected to a residue to separate, which contains elements of the platinum group, and these residues, the Platinum group elements are then combined and used.

Short description the figures

1 FIG. 12 depicts a process schematic showing the outline of a solution separation process according to the invention, illustrating the steps for separating both selenium / tellurium and platinum group elements from a material containing selenium / tellurium and platinum group elements.

2 is a process diagram showing the scheme of the steps from the treatment of a decoppered sludge to the separation process described in 1 is shown.

3 Figure 4 is a process schematic depicting the outline of a separation process according to the invention showing other stages for separating both selenium / tellurium and platinum group elements from a material containing selenium / tellurium and platinum group elements.

4 FIG. 3 is a process diagram showing an outline of the steps for treating a decoppered sludge by the separation process of the 3 represents.

5 Figure 3 is a process schematic illustrating an outline of the separation process according to the invention, showing other stages for separating both selenium / tellurium and platinum group elements from a material containing selenium / tellurium and platinum group elements.

6 Figure 3 is a process schematic depicting an outline of the separation process of the invention showing the steps for separating selenium and tellurium from a selenium / tellurium mixture.

7 Figure 3 is a process schematic depicting the outline of a separation process according to the invention, illustrating the steps of separating residual gold from a solution containing platinum group elements.

8A . 8B and 8C are process schemes which illustrate the outline of a separation process according to the invention and show the steps of a preferred combination of the separation process according to the invention.

Best implementation the invention

in the The following is a more detailed description of the separation process of the invention given.

A first separation process according to the invention is carried out using the 1 described. As shown in the figure, the first separation method according to the present invention is a solution treatment method for a material containing selenium and platinum group elements in which a flux containing a mixture of sodium hydroxide and sodium nitrate is added to the material, the selenium and Containing platinum group elements, the mixture is melted by heating to a temperature exceeding the eutectic temperature of the flux, and the resulting melt is leached with water to give a solid-liquid separation, thereby forming the mixture into a liquid fraction, the sodium selenite and a residue containing platinum group elements is separated.

For example, material containing selenium and platinum group elements may utilize the extraction residue obtained following solvent extraction of gold from leaching with hydrochloric acid from a decuperated slurry. This decuppressed sludge contains large quantities of precious metals such as gold, silver, platinum group elements, selenium, and tellurium. The treatment process for the sludge is in the 2 shown. As shown in the figure, the decuppressed sludge is slurried by the addition of hydrochloric acid and hydrogen peroxide, and this slurry is then filtered to separate into a primary silver-containing leach residue and a brine containing platinum group, selenium, and tellurium-containing brine result. Following the adjustment of the liquor liquid characteristics, a solvent is used to extract gold from the liquor. The liquid extraction residue contains the remaining elements of the platinum group, selenium and tellurium. Subsequently, sulfur dioxide is added to this post-extraction liquid to sequentially reduce and precipitate selenium and then tellurium. Tellurium has a lower reduction potential than selenium, and tellurium precipitates after the precipitation of selenium and thereby tellurium and selenium can be separated from each other. By this reduction, platinum group elements together with selenium are precipitated, and the platinum group and selenium containing precipitate elements can be heated to concentrate the platinum group elements and distill the selenium. The residue following the distillation and separation of selenium contains platinum group elements and undistilled selenium.

Materials containing selenium and platinum group elements, such as the above distillation residue, are mixed with a flux containing a mixture of sodium hydroxide (NaOH) and sodium nitrate (NaNO ₃ ), and the resulting mixture is melted by heating to a temperature equal to the temperature exceeds the eutectic temperature of the flux. This heating and melting converts the selenium to a predominantly tetravalent state, forming sodium selenite (Na ₂ SeO ₃ ), which subsequently dissolves. The reason for using a mixture of sodium hydroxide and sodium nitrate as a flux is that when sodium hydroxide alone is used, the supply of oxygen from the atmosphere is inadequate, resulting in production of sodium selenide (Na ₂ Se), and the sodium selenide changes into metallic selenium and precipitates with water during leaching, which means that the elements of the platinum group and selenium can not be physically separated. Moreover, if only sodium nitrate is used as the flux, the oxidizing power becomes very strong, resulting in an increase in the proportion of undesirable hexavalent selenium.

Around to allow the reduction in the melt temperature is the composition the melt preferably near a eutectic composition. Specifically, the ratio is of sodium hydroxide, sodium nitrate, preferably in the range of 75 : 25 to 85:15 (molar ratio).

In addition, the heating temperature must be at least the eutectic temperature of the flux (258 ° C), and since this flux must have adequate fluidity and must be able to leach the selenide materials, a temperature in the range of 350 to 450 ° C is preferred. At temperatures within this range, the sodium nitrate (NaNO ₃ ) generates oxygen, however, the probability of NOx generation is lower, whereas when the temperature exceeds the above range, the proportion of formation of NO x is increased and the oxidizing power also increases Proportion of hexavalent selenium increases.

in the Following the addition of the above melt to the selenium and Elements of the platinum group-containing material and then heating to melting the flux, the product is leached with water, a solid-liquid separation to effect. Sodium selenite dissolves in water, whereas the elements of the platinum group in the Residue remain and accordingly, by performing a leaching the above melt with water and then filtering the mixture in a filtrate containing sodium selenite and a solid residue, of the platinum group elements. The filtrate contains essentially no platinum group elements, resulting in effective separation of selenium from the elements of the platinum group shows. The Elements platinum group contained in the solid residue by adding an oxidizing agent such as hydrogen peroxide with hydrochloric acid drained. The resulting mixture is then filtered to remove the To obtain a filtrate, that contains the elements of the platinum group.

Accordingly, according to a first separation method according to the invention, the platinum group selenide element type material, which is substantially insoluble in conventional industrial wet processes, can be almost completely dissolved and the production of hexavalent selenium remains a problem in dry processes , can be suppressed to a low content. In addition, only water is used to dissolve the selenium and leach it out of the melt used, which means that the cost of treatment can be reduced.

The following is a description of a second preferred separation procedure according to the invention using 3 , As in 3 As shown, this second separation method of the invention is a separation method in which the material containing selenium and platinum group elements is leached with alkali at a high temperature, whereby the selenium and the like migrate into the liquid, and a solid-liquid separation subsequently occurs to separate the mixture into a solid fraction containing platinum group elements and a liquid fraction containing selenium and the like.

A another form of the second separation method of the invention further comprises dissolving and separation process of platinum group elements in which hydrochloric acid and an oxidizing agent to the separated solid fraction by Leaching with alkali is made, joining, causing the elements dissolved the platinum group become. About that In addition, the second separation method also includes a method in the leaching with alkali at high temperature causes that Both selenium and tellurium migrate into the liquid phase, causing a separation of the elements of the platinum group takes place, and a process in which the platinum group elements of one or more of the include several of rhodium, ruthenium, palladium and platinum. According to the invention relates a material that contains selenium and platinum group elements a material composed of platinum group elements, such as rhodium containing selenium and the like. Furthermore the term "selenium and the like "selenium and / or tellurium.

For example, as described above, the material containing selenium and platinum group elements may utilize the process precipitation of an extraction residue formed on the solvent extraction of gold from the hydrogen chloride liquor of a decoppered slurry. This decuppressed sludge contains large quantities of precious metals such as gold, silver, platinum group elements, selenium, and tellurium. The treatment process for the sludge is in the 4 shown. As shown in the figure, the decuppressed sludge is slurried by the addition of hydrochloric acid and hydrogen peroxide, and this slurry is then filtered to be separated into a primary silver-containing residue and a brine, the gold, platinum group elements, selenium, and tellurium contains to effect. Following the adjustment of the liquid characteristics of the liquor, a solvent extraction takes place to separate gold from the liquor. The post-extraction fluid contains the remaining elements of the platinum group, selenium and tellurium. Subsequently, sulfur dioxide is added to this post-extraction liquid to precipitate the platinum group, selenium and tellurium elements which are recovered as a process precipitate.

During the Reduction and precipitation of selenium and tellurium from the above post-extraction liquid by addition of sulfur dioxide, since tellurium is a lower Having reduction potential as selenium, tellurium after precipitation of selenium precipitated and accordingly can the two elements by filtering off the Selenausfällung and subsequent Addition of further sulfur dioxide to the filtrate to precipitate tellurium, be separated and won. During this reduction process The elements of the platinum group coincide with both the selenium and with tellurium. The present invention may include the precipitation of Selenium or precipitate of tellurium as starting material, the selenium / tellurium and elements of Contains platinum group, use.

The Leaching the selenium and platinum group-containing material with alkali is typically under an alkali concentration of at least 1 mole / liter performed and concentrations in the range of 5 moles / liter to 8 moles / liter are preferred. If it is ensured that the alkali concentration is at least 1 mole / liter, a strongly alkaline environment of at least pH 14 is generated, resulting in a reduction of the oxidation-reduction potential of Selenium and tellurium leads what means that selenium and tellurium in the alkaline solution at solved normal pressure can be without having to use an oxidizing agent. As the progression the dissolution reaction of selenium and tellurium occurs slowly at room temperature, that will Leaching typically at a temperature of at least 60 ° C and preferably at a temperature of about 80 ° C carried out.

The Leaching with alkali causes the dissolution of selenium and tellurium in the alkali solution, where they are dispersed in colloidal form. In contrast to do not become platinum group elements such as rhodium and palladium solved and remain in the solid phase. By filtering the resulting mixture will it be possible in a dispersion containing selenium and / or tellurium and a separate solid fraction containing elements of the platinum group.

Following the above solid-liquid separation, an oxidizing agent such as hydrogen peroxide and hydrochloric acid are added to the filtered solid fraction, thereby dissolving the platinum group elements such as platinum, palladium, rhodium and ruthenium. The elements of platinum Group are oxidized by hydrogen peroxide and then form chloride complexes with the chlorine ions, whereby they can be stabilized and dissolved in the aqueous phase. The hydrogen peroxide is added in an amount necessary to convert the platinum group elements into ions having stable oxidation numbers, namely the amount required to convert platinum to the tetravalent form, palladium to a divalent form, and rhodium and ruthenium to trivalent Transform forms. The amount of hydrochloric acid which is used is sufficient to PtCl ₆ ^-, to produce RhCl ₆ ^3-, and RuCl ₆ ^3-, and to leave free hydrochloric acid is at least 2 mol / L ^-, PdCl. ₄ The reaction temperature is typically at least 60 ° C to accelerate the reaction and is typically not more than 80 ° C to avoid decomposition of the hydrogen peroxide, and a temperature of about 70 ° C is preferred. The dissolution treatment makes it possible to obtain a hydrochloric acid solution containing dissolved platinum, palladium, rhodium and ruthenium.

According to the second Separation method of the invention by subjecting a selenium and elements the platinum group containing material leaching with alkali at a treatment temperature in the range of 60 to 80 ° C, selenium and tellurium dissolved and of the platinum group elements at normal temperature and be separated without using an oxidizing agent. Accordingly can Selenium and tellurium are easily separated from a process precipitate, the Contains selenium and tellurium as well as elements of the platinum group and the Elements of the platinum group can can be obtained selectively with a yield of 95 or higher. Because beyond that the elements of the platinum group during leaching with alkali are not oxidized, are highly insoluble oxides, such as rhodium oxide and ruthenium oxide not formed, which means that the elements of the platinum group are then easily dissolved can. The elements of the platinum group can in the leaching of the residue then with alkali be oxidized in the presence of hydrochloric acid, so Chloride complexes and a solution to form elements of the platinum group. The dissolved selenium and tellurium will be dispersed in colloidal form and can be neutralized as metals the lye are precipitated and accordingly These two metals can also be easily won. Usual leaching procedure with alkali, which use an oxidizing agent, lead the Leaching under pressure and since they produce sodium selenate and / or sodium selenite, is the subsequent one Recovery of selenium is time consuming. In contrast, it is by the inventive method possible, To dissolve selenium and tellurium and it will be possible to separate these elements from the elements of the platinum group, and Although at atmospheric pressure without the use of an oxidizing agent, what means the control of the process and the recovery treatment are much easier.

The following is a third preferred separation method of the invention using 5 described. As shown in the figure, this third separation method of the invention is a method for separating both selenium and platinum group elements from a material containing selenium / tellurium and platinum group elements, which comprises an alkali leaching process (ii) wherein the selenium / Tellurium and platinum group-containing material is subjected to alkali treatment at high temperature, whereby the material is separated into a liquor containing selenium / tellurium and a caustic residue containing platinum group elements, and an alkali fusion process (i) with addition of a mixture sodium hydroxide and sodium nitrate to a residue from the distillation treatment of a material containing selenium and platinum group elements, then heating to a temperature exceeding the melting temperature (eutectic) of the mixture, whereby selenium / tellurium is dissolved, followed by leaching with water the mixture into a Lye containing selenium / tellurium and separating a lye residue containing elements of the platinum group.

[Selenium / tellurium and elements the platinum group containing material]

As described above, as the material containing selenium / tellurium and platinum group-containing elements, for example, precipitation of a reduction process of an extraction residue due to the solvent extraction of gold may be precipitated from the hydrochloric acid solution of decuperated sludge. This decuppressed sludge contains large quantities of precious metals such as gold, silver, platinum group elements, selenium, and tellurium. Specifically, the material containing selenium / tellurium and platinum group elements is obtained by treating the decuperated sludge in the following manner. First, the decomposed sludge is slurried by the addition of hydrochloric acid and hydrogen peroxide, and the slurry is then filtered to separate into a residue containing primarily silver from a brine containing gold, platinum group elements, selenium, and tellurium. Following the adjustment of the liquid characteristics of the liquor, solvent extraction using DBC or the like is used to separate gold from the liquor. The post-extraction fluid contains the elements of the platinum group as well as selenium and tellurium. Sulfur dioxide and in particular sulfur dioxide gas are then introduced into this post-extraction liquid in a sufficient amount, to maintain the selenium concentration in the liquid at a level of 3 g / liter or higher, whereby the selenium is reduced and precipitated and the separation from the remaining post-extraction liquid occurs. Further, sulfur dioxide is introduced into the remaining post-extraction liquid from which the selenium was separated, whereby the residual selenium is reduced and precipitated, together with tellurium, which can be separated by subsequent filtration.

The third separation method according to the invention can the post gold extraction liquid use as described above as a liquid, containing selenium / tellurium and platinum group elements. Furthermore For example, in the separation process, the reduction precipitation of the above post-gold extraction liquid or the distillation residue, in the subsequent distillation is produced, used as a material, the selenium / tellurium and Contains elements of the platinum group. It can additionally also waste water from a platinum production or other solutions, contain the selenium / tellurium and platinum group elements, like that Wastewater, also used as material, selenium / tellurium and elements of the platinum group liquid contains.

at the reduction treatment of the above post gold extraction liquid can, because selenium and tellurium are reduced and precipitated, since tellurium is a lower one Having a reduction potential as selenium, the tellurium falls after the precipitation of Selenium off and then by filtering off the selenium precipitation and subsequently can by adding further sulfur dioxide to the filtrate to precipitate the Tellurs, the two elements are separated and won. During this Reduction process, the elements of the platinum group fall both with selenium as well as tellurium.

The Materials containing selenium / tellurium and platinum group elements obtained in this way are used in a subsequent alkali leaching process and an alkali fusion process. In this case will the selenium, the first in the reduction of the extraction residue fails, preferably subjected to distillation to the recovery of to allow high purity selenium and the residue (Distillation residue) is subjected to an alkaline melting treatment, whereas tellurium, that is precipitated, subsequently is preferably subjected to alkali leaching treatment. Of the distillation residue includes compounds such as palladium selenide and is stable and accordingly can selenium by dissolving can not be achieved with alkali. By melt treatment of the distillation residue can the selenium is effectively processed. In contrast, have that into tellurium precipitation incorporated rhodium and ruthenium a relatively higher content than that in selenium precipitation and if accordingly the tellurium precipitation of a Alkaline melt is subjected, insoluble oxides can be formed, whereby the subsequent one Leaching step with hydrochloric acid is difficult. Accordingly becomes the tellurium precipitate preferably leached with alkali.

[Alkali Fusion]

The above selenium / tellurium and platinum group-containing material such as the selenium precipitate or the above-mentioned distillation residue is subjected to alkali smelting treatment. In this alkali smelting treatment, a flux containing a mixture of sodium hydroxide (NaOH) and sodium nitrate (NaNO ₃ ), to the selenium precipitate or the selenium distillation residue, and the resulting mixture is heated by heating to a temperature exceeding the melting point (eutectic temperature) of the flux. This heating and melting converts the selenium to a predominantly tetravalent state, forming sodium selenite (Na ₂ SeO ₃ ), which subsequently dissolves. The reason for using a mixture of sodium hydroxide and sodium nitrate as a flux is that when sodium hydroxide alone is used, the supply of oxygen from the atmosphere is inadequate, resulting in production of sodium selenide (Na ₂ Se), and this sodium selenide is converted into metallic selenium and precipitates with water during leaching, which means that the elements of the platinum group and selenium can not be physically separated. Moreover, if only sodium nitrate is used as the flux, the oxidizing power becomes too strong, leading to an increase in the proportion of undesirable hexavalent selenium.

To reduce the melt temperature, the composition of the flux is preferably close to a eutectic composition. Specifically, the ratio of sodium hydroxide: sodium nitrate is preferably in the range of 75:25 to 85:15 (molar ratio). Moreover, the heating temperature must be at least the eutectic temperature of the flux (258 ° C), and since the flux must have adequate fluidity and must be able to leach the selenide materials, a heating temperature in the range of 350 to 450 ° C is preferred. At temperatures within this range, the sodium nitrate (NaNO ₃ ) produces oxygen, but produces less NOx, whereas when the temperature exceeds the above range, the level of NOx formation increases and the oxidizing power also increases, thereby increasing the level of hexavalent selenium increases.

in the Following the addition of the above flux to the selenium and platinum group-containing material, and then heating for Melting the agent, the molten product is leached with water, to effect a solid-liquid separation, Sodium selenite dissolves in water, whereas the elements of the platinum group in the Residue remain and, accordingly, by leaching the above Melt with water and then filter the mixture in a filtrate containing sodium selenite and a solid residue, of the platinum group elements. The filtrate contains substantially no elements of the platinum group, what an effective separation of Indicates selenium from the elements of the platinum group. The elements of Platinum group, which are contained in the solid residue by addition of hydrochloric acid together with an oxidizing agent, like hydrogen peroxide, dissolved. The resulting mixture is then filtered to obtain a filtrate win, which contains the elements of the platinum group.

[Alkali leaching process]

The Selenium / tellurium and platinum group elements is subjected to a leaching treatment with alkali. The leaching with alkali is typically carried out under an alkali concentration of at least 1 mole / liter, and concentrations in the range of 5 Moles / liter to 8 moles / liter are preferred. If it is certain that the alkali concentration is at least 1 mol / liter a strong alkaline environment of at least pH 14 obtained what a reduction of the oxidation-reduction potential caused by selenium and tellurium, which means selenium and tellurium in the alkaline solution solved at normal pressure can be without having to use an oxidizing agent. As the progression this dissolution reaction of selenium and tellurium occurs slowly at room temperature, typically at a temperature of at least 60 ° C and preferably at one Temperature of about 80 ° C drained.

The Leaching with alkali causes the release of selenium and tellurium in the alkali solution, where they are dispersed in colloidal form. In contrast to this become the elements of the platinum group, such as rhodium and palladium, unsolved and remain in the solid phase. By filtering the resulting mixture is a separation into a liquor containing selenium and / or tellurium and a solid fraction containing elements of the platinum group allows.

If following the above solid-liquid separation sulfuric acid or Hydrochloric acid be added to the selenium / tellurium-containing filtrate for neutralization, develops a black colored Precipitate of metallic selenium and / or metallic tellurium and the color of the solution brightens gradually from deep purple until the liquid is transparent at about pH 7 becomes. The yield of this Selenausfällung and / or Tellurausfällung lies typically at 99% or above, whereby metallic selenium and / or metallic tellurium with high quality can be won. If instead of sulfuric acid or hydrochloric acid Used nitric acid the oxidizing power of nitric acid causes the oxidation and dissolution of Selenium / tellurium, causing the precipitation not possible becomes. About that In addition, the temperature of the liquid is preferably 60 to 80 ° C. If neutralization at a liquid temperature within this area performed can be obtained metallic selenium with good filterability become.

An oxidizing agent such as hydrogen peroxide and hydrochloric acid are added to the filtered solid fraction containing the platinum group elements, thereby making it possible to dissolve the platinum group elements such as platinum, palladium, rhodium and ruthenium. The platinum group elements are oxidized by hydrogen peroxide and then form chloride complexes with the chloride ions, allowing them to be stably stabilized and dissolved in the liquid phase. The hydrogen peroxide is added in an amount necessary to convert the platinum group elements into ions having stable oxidation numbers, namely the amount required to convert platinum to the tetravalent form, palladium to a divalent form, and rhodium and ruthenium to trivalent Transform forms. The amount of hydrochloric acid which is used is preferably sufficient to PtCl ₆ ^-, PdCl ₄ ^- to form, RhCl ₆ ^3-, and RuCl ₆ ^3-, and to leave free hydrochloric acid is at least 2 moles / liter. The reaction temperature is typically at least 60 ° C to accelerate the reaction and is typically not more than 80 ° C to avoid decomposition of the hydrogen peroxide, and a temperature of about 70 ° C is preferred. The dissolution treatment makes it possible to obtain a hydrochloric acid solution containing dissolved platinum, palladium, rhodium and ruthenium.

As mentioned above, by treating a material containing selenium and platinum group-containing elements by alkali leaching at a treatment temperature in the range of 60 to 80 ° C, selenium and tellurium can be dissolved and separated from the platinum group elements at normal pressure without using an oxidizing agent. Accordingly, selenium and tellurium can be easily separated from a process precipitate, selenium and tellurium, as well as platinum group elements and the elements of the platinum group can be selectively recovered in a yield of 95% or higher. Moreover, since the elements of the platinum group are not oxidized during this alkali leaching, highly insoluble oxides such as rhodium oxide and ruthenium oxide are not generated, which means that the platinum group elements can then be easily dissolved. The elements of the platinum group can then be oxidized upon leaching the residue with alkali in the presence of hydrochloric acid to form chloride complexes and a solution of platinum group elements. The dissolved selenium and tellurium are dispersed in colloidal form and can be precipitated as metals by neutralizing the brine with either sulfuric acid or hydrochloric acid and, accordingly, these two metals can also be easily recovered. Conventional alkali leaching processes using an oxidizing agent require leaching under pressure and sodium selenate and / or sodium selenite are formed, and the presence of hexavalent selenium means that removal of selenium from the waste water becomes difficult. In contrast, by the method of the present invention, it becomes possible to dissolve selenium and tellurium and the separation of these elements from platinum group elements can be carried out at normal pressure without using an oxidizing agent, which means that the control of the process and the recovery treatment without production of hexavalent selenium can be performed.

As As described above, in the alkaline melting process, selenium and / or tellurium in water in the form of sodium selenite or sodium tellurite solved and subsequently from the lye residue, which contains the elements of the platinum group, separated. However, you can the separated liquor still small residual amounts of elements the platinum group in addition to selenium / tellurium and therefore the aqueous liquor is preferably in recycled the foregoing alkali leaching and leaching with Alkali, together with the selenium / tellurium and elements of the Platinum group containing material. This recycling treatment concentrated selenium / tellurium.

on the other hand becomes the leaching residue, contains the elements of the platinum group, which in the alkaline fusion process is obtained with an oxidizing agent such as hydrogen peroxide together with hydrochloric acid combined in the same manner as the residue from the Alkaliauslaugverfahren, which the platinum group elements, such as platinum, palladium, rhodium and Ruthenium solved The elements of the platinum group are hydrogen peroxide oxidized and then formed With the chlorine ions chloride complexes, making them stable in the liquid phase solved can be. This dissolution treatment allows a hydrochloric acid solution, the dissolved Platinum, palladium, rhodium and ruthenium. This chlorination treatment is preferably carried out together with the leaching residue which obtained in the alkali leaching process.

According to the third Separation method of the invention will be the selenium / tellurium among elements The platinum group-containing material is treated using a combination of an alkaline leaching process in which an alkali leach performed at high temperature and an alkali fusion process in which a mixture of Sodium hydroxide and sodium nitrate are added and the mixture is melted by heating to a temperature that exceeds the melting temperature (eutectic), to dissolve the selenium / tellurium and as a result you can Selenium / tellurium and the elements of the platinum group concentrated and almost complete be gained, making it possible is an easily refined hydrochloric acid solution in the subsequent one To introduce a refining step, making platinum group elements and selenium / tellurium simple and effective can be separated at low cost, made of a material containing selenium / tellurium and elements contains the platinum group.

In the following, a fourth preferred separation method according to the invention will be noted 6 described.

The The fourth separation method described below is a treatment method for selenium / tellurium, in which a selenium / tellurium mixture in a copper smelting and refining process is introduced to form an alloy of selenium and tellurium with copper, these Alloy is subjected to copper electrolysis to make copper electrolytic whereas selenium and tellurium are in the mud of copper electrolysis be accumulated and this sludge of the copper electrolysis is then a subjected to oxidative leaching with sulfuric acid to tellurium to solve, whereby the tellurium can be separated from the selenium, which in the lye residue remains.

Like in the 6 In particular, an aforementioned material containing selenium / tellurium and platinum group elements is used as the selenium / tellurium mixture, and as described above, this material first undergoes an alkali leaching process in which the mixture is leached with alkali at a high temperature to effect separation into a selenium / tellurium-containing caustic and a caustic residue containing platinum group elements. Subsequently, sulfuric acid or hydrochloric acid is added to the brine to neutralize the brine and precipitate the selenium / tellurium mixture and this mixture is introduced into a copper refining process to form an alloy of selenium and tellurium with copper. This alloy is subjected to copper electrolysis to obtain electrolytic copper, whereby selenium and tellurium are enriched in the sludge of copper electrolysis, and this sludge of copper electrolysis is then subjected to oxidative leaching with sulfuric acid to elute the tellurium, thereby making possible the tellurium of Selenium, which remains in the lye residue to separate.

[Selenium / tellurium mixture]

at the fourth invention Separation method can be used as a selenium / tellurium mixture a treatment material which contains selenium / tellurium and platinum group elements a copper process. Specifically, this type of material, selenium / tellurium and contains elements of the platinum group that are in the first one until the third separation method was used.

This Selenium / tellurium and platinum group elements will follow an alkali display method and an alkali fusion method, such as described below. As in the case of the above In the fourth separation process, the separation process becomes selenium the first reduction of post-extraction fluid is obtained, preferably subjected to distillation to selenium to recover with high purity and the residue (distillation residue) is subjected to an alkaline melting treatment, whereas tellurium, that afterwards fails, is preferably subjected to alkali leaching treatment. Of the distillation residue includes compounds such as palladium selenide and is stable and accordingly can be a release of selenium can not be achieved by leaching with alkali. By Distilling the slag of the alkali melting treatment may be the selenium be processed effectively. In contrast, the rhodium and ruthenium incorporated in tellurium precipitation of relatively higher amount than that in selenium precipitation and if accordingly the tellurium precipitation of an alkaline melt is subject to precipitation insoluble Forming oxides, whereby the subsequent leaching step is made difficult with hydrochloric acid. Accordingly, the tellurium precipitation is preferably leached subjected to alkali.

[Alkali leaching process]

As described in the above separation method, the selenium / tellurium and elements of the platinum group containing leaching material with Alkali subjected. Alkali leaching typically becomes carried out at an alkali concentration of at least 1 mol / liter and Concentrations range from 5 moles / liter to 8 moles / liter prefers. If the alkali concentration is at least 1 mol / liter, a strongly alkaline environment of at least pH 14 achieves what to a reduction of the oxidation-reduction potential of selenium and tellurium leads, which means that selenium and tellurium are in the alkaline solution at Normal pressure solved can be without it being necessary to use an oxidizing agent. There the dissolution reaction of this Selenium and tellurium progresses slowly at room temperature leaching typically at a temperature of at least 60 ° C and preferably carried out at a temperature of about 80 ° C.

The Leaching with alkali leads to a release of selenium and tellurium in the alkaline solution, where they are in colloidal Form are dispersed. In contrast, the elements become the platinum group, such as rhodium and palladium are not dissolved and remain in the solid phase. By filtering the resulting mixture is a separation into a liquor containing selenium and / or tellurium and a solid fraction containing elements of the platinum group possible.

The above leaching with alkali may also be carried out on a combination of the material containing selenium / tellurium and platinum group elements and the liquor obtained by subjecting the residue from the above distillation treatment to alkali smelting treatment. The selenium precipitate obtained by reduction treatment of the selenium / tellurium and platinum group elements or the residue obtained from the distillation treatment of this reduced selenium precipitation are combined with a flux containing a mixture of sodium hydroxide (NaOH) and sodium nitrate (NaNO ₃ ) and the resulting mixture is passed through Heating to a temperature exceeding the melting point (eutectic temperature) of the flux melted. Heating and melting convert the selenium to a predominantly tetravalent state, forming sodium selenite (Na ₂ SeO ₃ ), which subsequently dissolves. This alkali melting treatment effects the dissolution of selenium / tellurium, followed by leaching with water to separate the mixture into an alkali containing selenium / tellurium and a leaching residue containing platinum group elements. This liquor may be added to the alkali leaching process of materials containing selenium / tellurium and platinum group elements, and leached with alkali as described above. By using the liquor obtained from this alkali fusion process, it becomes possible to improve the overall yield of selenium / tellurium for the entire treatment process.

Afterwards the above solid-liquid separation When leaching with alkali develops when sulfuric acid or Hydrochloric acid be added to the selenium / tellurium-containing filtrate for neutralization, a black colored precipitation of metallic selenium and / or metallic tellurium and the color the solution brightens gradually from deep purple until the liquid is transparent at about pH 7 becomes. By performing a Solid-liquid separation may be a mixture of metallic tellurium and metallic selenium be won. The yield of this selenium / tellurium mixture is typically at 99% or above, thereby it possible will win metallic selenium and / or metallic tellurium of high quality. If instead of sulfuric acid or hydrochloric acid nitric acid is used, the oxidizing power of nitric acid causes the Oxidation and dissolution of selenium / tellurium, which means that precipitation is not possible. The temperature of the liquid is preferably from 60 to 80 ° C. If neutralization at a liquid temperature within this area performed is, a selenium / tellurium mixture can be obtained, which is easy to filter is.

at the fourth invention Separation method, the above selenium / tellurium mixture in a Copper smelting and refining process introduced to make an alloy of To make selenium and tellurium with copper and this alloyed copper (raw Copper) is subsequently added electrolyzed to obtain electrolytic copper, with selenium and tellurium accumulated within the mud of copper electrolysis become insoluble along with others Components. The copper electrolysis can under normal conditions for the Copper electrolysis performed become. The electrolysis of copper leads to an electrolytic High purity copper whereas selenium and tellurium make a mud of Form copper electrolysis together with other insoluble components, which were contained in the crude copper. If this mud of copper electrolysis an air oxidation in sulfuric acid is subjected to and a leaching treatment (leaching for copper removal) carried out The majority of the copper and tellurium in the sludge are present, solved become. The sulfuric acid electrolyte can be used as sulfuric acid for this Stage can be used. Will the dissolved copper liquor, the tellurium contains brought into contact with metallic copper, it forms Kupfertellurid what means that tellurium can be obtained as a copper telluride From an industrial point of view, tellurium containing dissolved Copper liquor preferably through a tower packed with copper chips passed to win the copper telluride. On the other hand remains the selenium in the lye residue (de-coppered sludge) and accordingly, this leaching used to remove copper for separation of selenium and tellurium become.

in the Connect to the above leaching to remove copper the caustic containing copper and selenium is put into the electrolytic stage returned to the copper and Copper is recovered as electrolytic copper. As above described, the selenium accumulates in the sludge of the copper electrolysis and, accordingly, by repeating the oxidizing leaching with sulfuric acid (Leaching to remove copper) of the sludge of copper electrolysis the selenium is concentrated within the decomposed sludge. Furthermore contains this decoked sludge also contains large amounts of precious metals, such as gold, silver, platinum group elements and lead, and accordingly can through a chlorinating leaching decuppressed sludge by introducing an oxidizing agent, such as hydrogen peroxide, chlorine gas together with Hydrochloric acid or the like, these precious metals are dissolved and then put under Application of a treatment method that is useful for obtaining each of these Precious metals is suitable to be won.

According to one example for The process of recovering precious metals will be that in the mud contained silver and lead through the above chlorination leaching in insoluble Chlorides converted to gold, elements of the platinum group, selenium and tellurium dissolved in the lye be, and a solid-liquid separation is subsequently performed to a separation into a lye filtrate, the gold and platinum group elements and the like and a lye filter residue, containing silver and lead, to effect and the treatment method described above will follow applied to silver and lead from this silver and lead containing Residue to separate. Furthermore can use a solvent extraction be to gold from the lye filtrate, the tellurium and elements of the Contains platinum group and the like, and then extract performed a reduction, to recover the gold, whereas the post-extraction liquid a distillation treatment, the selenium and the tellurium is reduced and the resulting reduction precipitate becomes used to the treatment according to the invention to repeat, making it possible Selenium and tellurium will concentrate and with good effectiveness to win.

According to the fourth method of the present invention, a selenium / tellurium mixture is introduced into a copper refining process to form an alloy of selenium and tellurium with copper, and this copper alloy is electrolyzed to recover high purity electrolytic copper the selenium and tellurium are accumulated in the sludge of the copper electrolysis and then this sludge of the copper electrolysis is subjected to oxidative leaching with sulfuric acid (leaching to remove copper), the tellurium can be dissolved in the solution and separated from the selenium and the dissolved tellurium can be separated and recovered by contact with metallic copper to form copper telluride. Moreover, the selenium remaining in the residue of the copper liquor can be separated and recovered by reduction treatment following the performance of a noble metal recovery process such as a gold extraction process.

The following is a description of a fifth preferred separation method according to the invention with reference to FIG 7 , Like in the 7 5, the fifth separation process is a treatment process for separating gold from a solution containing platinum group elements, wherein a material containing selenium / tellurium and platinum group-containing elements is subjected to alkali treatment to separate into a caustic solution, hydrochloric acid is added to this platinum group-containing residue in the presence of an oxidizing agent, a solid-liquid separation is carried out, and then hydroxylamine hydrochloride is added to the filtered solution, containing the elements of the platinum group, added to selectively reduce and precipitate gold.

Also at this fifth Separation method of the invention may be a selenium / tellurium and elements the platinum group-containing material used in a copper smelting process was obtained in a similar way as for described the first separation method used.

[Alkali Treatment]

The Selenium / tellurium and platinum group elements is subjected to an alkali treatment and into a lye containing selenium / tellurium and a Residue, contains the elements of the platinum group, separated. As above This alkali treatment can be either an alkali leaching process or an alkali fusion process or both. In such cases, though both the alkali leaching process and the alkali smelting process carried out The selenium first becomes the reduction of the above Post-extraction liquid fails, preferably subjected to distillation to high purity selenium to win, and the residue (Distillation residues) is subjected to an alkali melting treatment, whereas tellurium, subsequently fails, is preferably subjected to leaching with alkali. The distillation residue includes compounds such as palladium selenide, and is stable and accordingly can a dissolve of selenium can not be achieved by leaching with alkali. By Subjecting the distillation residue In alkali smelting treatment, selenium can be effectively processed. In contrast, in the tellurium precipitate containing rhodium and Ruthenium of relatively higher Amount than that in selenium precipitation and if accordingly the tellurium precipitation one When subjected to melting with alkali, it can be insoluble oxides form, creating a subsequent Leach with hydrochloric acid is difficult. Accordingly, tellurium precipitation becomes preferable subjected to leaching with alkali.

[Alkali melting]

In the leaching with alkali, the selenium precipitate, the material obtained by reduction treatment of a selenium / tellurium and platinum group-containing material, or the residue obtained from the distillation treatment of this reduced selenium precipitate, is combined with a flux comprising a mixture of sodium hydroxide (NaOH). and sodium nitrate (NaNO ₃ ), and the resulting mixture is melted while heating to a temperature exceeding the melting point (eutectic temperature) of the flux. This heating and melting mainly converts the selenium to the tetravalent state, forming sodium selenite (Na ₂ SeO ₃ ), which subsequently dissolves. This alkali melting treatment effects the dissolution of selenium / tellurium and leaching with water is then used to separate the mixture into an alkali containing selenium / tellurium and a caustic residue containing the elements of the platinum group. This liquor may be recycled to the alkali leaching process of materials containing selenium / tellurium and platinum group elements and subjected to leaching with alkali as described above. By using the liquor obtained from this alkali fusion process, it becomes possible to improve the overall yield of selenium / tellurium for the entire treatment process.

[Leaching with alkali]

The leaching treatment of the selenium / tellurium and platinum group-containing material with alkali is typically conducted under alkali concentration of at least 1 mol / L, and concentrations in the range of 5 mol / L to 8 mol / L are preferred. If it is ensured that the alkali concentration is at least 1 mol / L, then a strong alkaline environment of at least pH 14, which results in a reduction of the Oxidati This results in selenium and tellurium being able to be dissolved in the alkaline solution at atmospheric pressure without the use of an oxidizing agent. As this selenium and tellurium dissolution process proceeds slowly at room temperature, leaching is typically conducted at a temperature of at least 60 ° C and preferably at a temperature of about 80 ° C.

The Leaching with alkali leads to a dissolution of selenium and tellurium in the alkaline solution, where they are in colloidal Form are dispersed. In contrast, the elements remain the platinum group, such as rhodium and palladium in the solid phase and will not be solved. By filtering the resulting mixture, it becomes possible to obtain a Selenium and / or tellurium-containing liquor and a solid fraction, contains the elements of the platinum group to separate.

at the method according to the invention hydroxylamine hydrochloride is added to the solution, the platinum group elements contains and was obtained by alkali treatment as described above, to selectively reduce and precipitate gold. Provided that hydroxylamine hydrochloride As a reducing agent, gold can be selectively reduced and precipitated even if the solution of the platinum group elements is hydrochloric acid. The amount of added Hydroxylamine hydrochloride is typically in the range of 1.3 up to 1.6 equivalents, based on the amount of gold. If the amount is less than 1.3 equivalents, then the reduction of gold unsatisfactory, whereas if the amount exceeds 1.6 equivalents, the elements of the platinum group, and in particular palladium, together be reduced with the gold, which means that gold is not selective can be won. The reduction temperature is preferably at least 60 ° C. At temperatures of less than 60 ° C, the reduction reaction slow, making the process industrially unsuitable.

Therefore can according to this separation process according to the invention remaining gold, in a solution contained by elements of the platinum group that was obtained by treating a selenium / tellurium and platinum group elements containing material, precipitated and separated with high efficiency. That's why separation process according to the invention ideal for use in a process where precious metals are made A sludge of copper analysis will be recovered and it will be for removal of gold during the separation stage and recovery stage of selenium / tellurium and elements of Platinum group from the reduction precipitation, which during the Reduction of a post-gold extraction fluid is obtained to remove.

The 8A . 8B and 8C are process diagrams illustrating the separation process according to the invention and show the steps within a preferred combination of the first to fifth separation processes according to the invention.

Like in the 8th It can be seen that by combining the preferred separation techniques described above, selenium, tellurium, platinum group elements and gold and the like can be readily separated from decuperated sludge, and more particularly from a material containing selenium / tellurium and platinum group elements. which was separated from a decuperated sludge.

Specifically, the first separation process substantially corresponds to the steps in FIG 8B from the NaOH melt to leaching with water and filtration and the second separation procedure essentially corresponds to the steps of eluting with NaOH until filtering. Moreover, the steps of eluting with NaOH until filtering and the steps of melting with NaOH to leaching with water and filtering are also substantially the same as the third separation method. The fourth separation method corresponds to the stages from the molten copper to the removal of tellurium in the 8C , The fifth separation process essentially corresponds to the stages in the 8B from leaching with NaOH to filtration and the steps in which the selenium / tellurium-containing liquor obtained in the steps from the NaOH melt to leaching with water and filtration, chlorination, filtration and subsequent removal of gold and filtration is subjected ,

in the The following are examples and comparative experiments for the present Invention specified. Unless otherwise indicated, refer the units% to weight percent (wt .-%).

example 1

Using 20 g of a platinum group element-containing material containing palladium selenide as a main component as the starting material, 21.7 g of sodium hydroxide and 11.5 g of sodium nitrate were mixed with the raw material, and the mixture was heated at 400 ° C for 2 hours to obtain a Melt heated. After cooling the melt, 500 ml of water was added, and the mixture was stirred for 1 hour and then filtered. 97.4% of the selenium from the above raw material was leached into the filtrate. In addition, platinum and palladium were not detected in the filtrate. The amount of hexavalent selenium in the filtrate was less than 10%. In the meantime, the filtered residue was again treated with 3N hydrochloric acid and on finally oxidized with hydrogen peroxide and dissolved. As a result, 95% of palladium and 99% or more of platinum were leached into the solution.

Example 2

With Exception of using 20.3 g of sodium hydroxide and 14.4 g of sodium nitrate the same method as in Example 1 was used to add 20 g of material, containing platinum group elements, which is palladium selenide as primary Component included, to heat and melt and then this melt was leached with water and filtered. The leaching amount of selenium in the filtrate was 98.2%. Platinum and palladium were not detected in the filtrate. In addition, the share was hexavalent selenium in the filtrate less than 10%. When the filtered Residue with 3N hydrochloric acid offset and then was oxidized and dissolved in hydrogen peroxide, the leach amount on palladium in the solution 95% and the leaching amount of platinum was 99% or more.

Example 3

With Excluding the use of 23.0 g of sodium hydroxide and 8.6 g of sodium nitrate was worked in the same manner as in Example 1 with heating and Melting 20 g of material containing platinum group elements and as the main component contained palladium selenide and then this melt leached with water and filtered. The leaching amount of selenium in the filtrate was 97.2%. Platinum and palladium were not detected in the filtrate. In addition, the share was hexavalent selenium in the filtrate less than 10%. When the filtered Slag is treated with 3N hydrochloric acid and then with hydrogen peroxide oxidized and dissolved was the leaching amount of palladium in the solution 95% and the leaching amount of platinum was 99% or more.

Example 4

5 kg of decoupled electrolysis sludge were dissolved in 5 L hydrochloric acid and 2 L of water added, hydrogen peroxide was gradually added to the Mixture added and the temperature of the liquid was at 70 ° C held to cause an oxidizing leaching. Subsequently was cooled and the leaching residue the chlorination was filtered, the acid concentration of the filtrate was adjusted and the filtrate was treated with 1.5 L dibutylcarbitol mixed, whereby the gold was extracted into the dibutylcarbitol. The respective concentration within the post-extraction fluid was 30 mg / L gold, 58.9 g / L selenium, 15 mg / L platinum and 172 mg / L palladium. Sulfur dioxide gas was used by this liquid for the reduction of Selenium at a liquid temperature from 80 ° C blown and then was cooled and the liquid is filtered. 901 g of this Selenausfällung were in the atmosphere 750 ° C to Separation of selenium distilled and upon receipt of 6.9 g of distillation residue was examined and a content of 45.2 palladium, 4.2% Platinum, 15.3% gold and 34.2% selenium found. 5.7 g of sodium hydroxide and 3.0 g of sodium nitrate became the distillation residue together and it was afterwards the same procedure as used in Example 1 to the To heat mixture and melt and then this melt was leached with water and filtered. The leaching amount of selenium in the filtrate was 98.4%. Platinum and palladium were not detected in the filtrate. In addition, the proportion of hexavalent selenium in the filtrate less than 10%. When the filtered Added with 3N hydrochloric acid slag and then in Hydrogen peroxide was oxidized and dissolved, was the leachate on palladium in the solution 95% and the leaching amount of platinum was 99% or more.

Comparative experiment 1

With Exception of substitution of the mixture of sodium hydroxide and sodium nitrate 27 g of sodium hydroxide alone was the same procedure as used in Example 1, containing the elements of the platinum group To heat material containing palladium selenide as the main component, and melted and then became this melt leached with water and filtered. The leaching amount of selenium in the filtrate was 33.6%, much lower than that value obtained in Example 1. Platinum and palladium were in the Filtrate not detected. About that In addition, the proportion of hexavalent selenium in the filtrate was less than 10%. When the filtered residue with 3N hydrochloric acid offset and then was oxidized and dissolved in hydrogen peroxide, the leaching rate on palladium in the solution 95% and the leaching rate of platinum was 99 or more.

Comparative experiment 2

Except for replacing the mixture of sodium hydroxide and sodium nitrate with 57.6 g of sodium nitrate alone, the same procedure as in Example 1 was followed by heating and melting the material containing platinum group elements with palladium selenide as the main component to become this melt then leached with water and filtered. The leaching rate of selenium in the filtrate was 98.5%. Platinum and palladium were not detected in the filtrate. However, the amount of hexavalent selenium in the filtrate was 25%, much higher than the value found in Example 1. When the filtered residue with 3N Chlorwas and then oxidized with hydrogen peroxide and dissolved, the leaching rate of palladium in the solution was 95% and the leaching rate of platinum was 99% or more.

Example 5

If 1 kg of selenium and platinum group elements (Se: 65%, Te: 30%, Pd: 5%, Pt: 0.5%, Rh: 0.2% and Ru: 0.4%) containing 10 material L of a 5 mol / L sodium hydroxide solution mixed and then at 80 ° C heated and kept at this temperature for 1 hour, dissolved the majority of the material forming a dark purple color Liquid. The liquid was cooled and filtered to give 65 g of residue. The analysis of this residue revealed elements of the platinum group, Pd, Pt, Rh and Ru as major components and the analysis results were Pd: 80%, Pt: 8%, Rh: 3% and Ru: 6%. The filtrate was a solution which contained 65 g / L Se and 30 g / L Te, and there were no elements the platinum group determined.

Example 6

If 1 kg of selenium and platinum group elements (Se: 65%, Te: 30%, Pd: 5%, Pt: 0.5%, Rh: 0.2% and Ru: 0.4%) containing 10 material L of a 5 mol / L sodium hydroxide solution mixed and then at 80 ° C heated and kept at this temperature for 1 hour, dissolved the majority of the material forming a dark purple color Liquid. The liquid was cooled and filtered to give 65 g of residue. The filtrate was one Solution, containing 65 g / L Se and 30 g / L Te, elements of the platinum group were not detected. The analysis of the residue revealed elements of the Platinum group, Pd, Pt, Rh and Ru as main components and the analysis results were Pd: 80%, Pt: 8%, Rh: 3% and Ru: 6%. This residue was dissolved in 400 ml of hydrochloric acid and 100 ml of water was added and the liquid temperature was at 70 ° C held and it gradually became Added 120 ml of hydrogen peroxide. After completion of the addition of hydrogen peroxide was the liquid chilled and filtered and then the filtrate was analyzed. It was found to contain it Pd: 74 g / L, Pt: 7 g / L, Rh: 2.8 g / L and Ru: 5.5 g / L.

Example 7

With Exception of the change the concentrations of sodium hydroxide to 1 mol / L and the expansion the heating time to 5 hours, leaching with alkali was the same as performed in Example 5. 75 g of residue were obtained. The main components in the residue were Pd, Pt, Rh, and Ru, and the analysis results gave Pd: 67%, Pt: 7%, Rh: 3% and Ru: 5%. The filtrate was a solution that 63 g / L Se and 28 g / L Te contained and became platinum group elements not determined.

Example 8

With Exception of the change the concentration of sodium hydroxide solution to 1 mol / L and the heating temperature to 60 ° C was leaching with alkali in the same manner as in Example 5 performed. There were 65 g of residue receive. The main components in the residue were Pd, Pt, Rh and Ru and the analysis results were Pd: 77%, Pt: 8%, Rh: 3% and Ru: 6%. The filtrate was a solution which contained 64 g / L Se and 29 g / L Te and they were not elements to determine the platinum group.

Comparative Experiments 3 and 4

With Exception of the change the concentration of the solution of sodium hydroxide to 0.5 mol / L was leached with alkali in the same manner as in Example 5, but dissolved Selenium and tellurium were not and the elements of the platinum group could can not be separated from the selenium and tellurium (comparative experiment 3).

Furthermore except for adjusting the reaction temperature to room temperature leaching with alkali is carried out in the same manner as in Example 5, however solved selenium and tellurium could not and the elements of the platinum group could can not be separated from the selenium and tellurium (comparative experiment 4)

Example 9

600 g of a distillation residue (Distillation residue a selenium precipitation: Primary component: Palladium selenide) of a reduction residue obtained by reduction treatment the post-gold extraction fluid from a sludge of copper electrolysis, were charged with 651 g of sodium hydroxide and 345 g of sodium nitrate, followed by reaction at 400 ° C for 2 hours brought. Following the cooling 15 L of water was added and the resulting mixture became subsequently Stirred for 1 hour and filtered to yield 15 L of filtrate and 348 g of filtered one Residue. The concentration of Se in the filtrate was 10.4 g / L, which is a leaching rate from 97.4 for Selenium from the distillation residue displays. Platinum and palladium were not detected in the liquor. Furthermore the level of hexavalent selenium in the fluid was less than 10%. The Analysis of the composition of the filtered slag yielded elements the platinum group as the main components and the respective concentrations Pd were 44%, Pt 5%, Rh 0.3% and Ru 1.0%.

Subsequently was 1 kg of tellurium precipitation (Se 65%, Te 30%, Pd 5%, Pt 0.5%, Rh 0.2%, Ru 0.4%) from the above Reduction precipitation with 10 L sodium hydroxide solution (Concentration 5 mol / L) and then kept at 80 ° C for 1 hour and the solution assumed a dark purple color. The liquid was then cooled and filtered to give 12.5 g of filtrate and 65 g of filtered residue. Analysis of the composition of the filtered residue revealed as the main components Platinum group elements and their respective concentrations were Pd 80%, Pt 8%, Rh 3% and Ru 6%. The Se concentration in the filtrate was 65 g / L and the Te concentration was 30 g / L and there were no elements the platinum group determined.

Subsequently were the filtered residues are mixed, it was 3N hydrochloric acid was added and the mixture was reslurried and then became Hydrogen peroxide at 70 ° C introduced, to cause oxidation. The resulting mixture was filtered and the concentration of the platinum group elements within the resulting hydrochloric acid solution (filtrate) Pd was 95 g / L (95%), Pt 8.5 g / L (99%), Rh 3.2 g / L (95%) and Ru 0.5 g / L (at least 95%) (where the values in parentheses are leaching rates).

Example 10

With Excluding the use of 609 g of sodium hydroxide and 432 g of sodium nitrate the same procedure was used as in Example 9, to heat 600 g of a selenium slag distillation residue and with alkali to melt and the resulting melt was then with Leached water and then filtered. The leaching rate of selenium in the filtrate was 98.2%. Platinum and palladium were in the filtrate not determined. About that In addition, the proportion of hexavalent selenium in the filtrate was less than 10%. Analysis of the composition of the filtered slag revealed elements of the platinum group as main components and the respective ones Concentrations were Pd 45%, Pt 5%, Rh 1% and Ru 2%.

Subsequently was 1 kg of tellurium precipitation from the above reduction precipitate mixed with 10 L of one Sodium hydroxide solution (concentration 5 mol / L) and then 1 hour at 80 ° C held, taking the solution dark purple colored. The liquid was then cooled and filtered to give 10 L of filtrate and 65 g of filtered residue. The Se concentration in the filtrate was 65 g / L and the Te concentration was 30 g / L and no platinum group elements were detected. Analysis of the composition of the filtered slag yielded elements the platinum group as main components and the respective concentrations were Pd 80%, Pt 8%, Rh 3% and Ru 6%.

Subsequently was the filtered residue is mixed, 2 L hydrochloric acid and 500 ml of water were added and the mixture became again slurried. The temperature became 70 ° C and 360 ml of hydrogen peroxide were gradually added to the Oxidation added. After complete addition of hydrogen peroxide the mixture was cooled and filtered. The concentration of the elements of the platinum group in The resulting filtrate was Pd 81 g / L, Pt 7 g / L, Rh 2.1 g / L and Ru 2.4 g / L.

Example 11

The Leach (filtrate), which in the leaching with alkali in Example 9 was obtained at 80 ° C and the filtrate was neutralized by the addition of sulfuric acid, being a black precipitate occurred until the liquid became transparent at about pH 7. The precipitate was filtered off and and an analysis of the composition yielded 68% metallic Selenium and 31% metallic tellurium.

Example 12

With Exception of the use of hydrochloric acid instead of sulfuric acid was the Example 11 was repeated and gave a similar analysis on metallic Selenium and metallic tellurium.

Comparative experiment 5

1 kg of tellurium precipitate was mixed with 1085 g of sodium hydroxide and 575 g of sodium nitrate and subsequently 2 hours at 400 ° C implemented, in the same way as the distillation residue Selenium of Example 9. It was then cooled, 25 L of water was added and the resulting mixture was then stirred for 1 hour and filtered and the concentrations in the filtrate showed a leaching rate of 97.4% by weight for Se and 98.1% for Te on. Platinum and palladium were not detected in the filtrate. The filtered residues were mixed, 3N hydrochloric acid was added and the mixture was reslurried and subsequently was hydrogen peroxide at 70 ° C introduced, to cause oxidation. The resulting mixture was filtered and the concentrations and leaching rates of the platinum group elements in the resulting hydrochloric acid solution (filtrate), Pd 95 g / L (95%), Pt 8.5 g / L (95%), Rh 1.3 g / L (39%) and Ru 1.5 g / L (14%) (where the values in parentheses are leaching rates), which is a considerable Leaching of leaching rates for Rh and Ru compared with Example 9 means.

Comparative experiment 6

Instead of the distillation residue submitting the selenium distillation of Example 9 to an alkaline melt, were 1 kg of the same residue the selenium distillation combined with 10 L 5 mol / L sodium hydroxide solution and the temperature was kept at 80 ° C, however, the selenium was almost not solved.

Example 13

If a material containing selenium / tellurium and platinum group elements (Se 65%, Te 30%, Pd 5%, Pt 0.5%, Rh 0.2% and Ru 0.4%) containing 1 kg of selenium / tellurium reduction precipitate, with 10 L of 5 mol / L sodium hydroxide mixed and then at 80 ° C was held to leach with alkali, the main part of the dissolved Materials, giving a dark purple liquid. The liquid was cooled and filtered to give 65 g of residue. The filtrate contained 65 g / L Se and 30 g / L Te and there were no elements of the platinum group detected. The temperature was kept at 80 ° C and it became sulfuric acid (50% concentration) added and it was further neutralized to pH 7, with a black colored Powder precipitated. The composition of this precipitate was 68.5% Se and 31.5% Te. About that In addition, the concentrations of Se and Te were those in the filtrate remained, 530 ppm and 210 ppm, respectively. The precipitate was transformed into a copper refining process introduced, an electrolytic refining was carried out and The anode sludge that was generated became the sulfuric acid electrolyte leached, with air being blown through the electrolyte. Of the Main part of the Te in the anode sludge was dissolved and the Te determination of the sludge after leaching gave 0.5%. Furthermore was not solved no Se was detected in the liquor and the Se determination of the Sludge after leaching was 8.3%. The lye was replaced by a Led with copper chips packed tower and Te was removed from the liquor recovered as copper telluride. In addition, remaining Se and dissolved gold in the sludge by oxidative leaching with hydrochloric acid from a solvent extraction of the gold, sulfur dioxide was introduced into the post-extraction liquid reduce and win the selenium. The analysis of the composition the above residue Leaching resulted in elements of the platinum group, Pd, Pt, Rh and Ru as major components and the respective determinations gave Pd 80%, Pt 8%, Rh 3% and Ru 6%. This residue was again with 2 L hydrochloric acid and slurried 500 ml of water and the liquid temperature was at 70 ° C kept and it gradually became Added 360 ml of hydrogen peroxide. After completion of hydrogen peroxide addition the mixture was cooled and filtered and the subsequent analysis of the resulting filtrate gave a content of Pd 81 g / L, Pt 7 g / L, Rh 2.1 g / L and Ru 2.4 g / L.

Example 14

600 g of a distillation residue (Se: 50%, Pd: 40%, Pt: 3%, Rh: 1 and Ru: 2%) obtained by reduction the post-gold extraction fluid a sludge of the copper electrolysis and subsequent distillation treatment, were mixed with 651 g of sodium hydroxide and 345 g of sodium nitrate and subsequently was 2 hours at 400 ° C to Effect of an alkali melt implemented. Subsequently was chilled and 15 L of water were added to the mixture and the resulting mixture was then stirred for 1 hour and filtered, leaching 97.4 g of the selenium into the filtrate, whereas platinum and palladium were not detected. Furthermore the level of hexavalent selenium in the fluid was less than 10%.

Example 15

To 1 kg of tellurium precipitate, obtained by introducing from further sulfur dioxide gas into the liquid after the separation Selenium precipitation in Example 14 was added 10 L of a 5 mol / L sodium hydroxide solution were added and the Alkali leaching was carried out at a temperature maintained at 80 ° C was, performed, the majority of the slag dissolved and the solution a dark one Purple color accepted. The liquid was then cooled and filtered to give 65 g of residue. The analysis of the residue revealed elements of the platinum group Pd, Pt, Rh and Ru as main components. This residue was reslurried in 2 L hydrochloric acid and 500 ml of water and the liquid temperature was at 70 ° C and 360 ml of hydrogen peroxide were added gradually. Upon completion of the addition of the hydrogen peroxide, the liquid became chilled and filtered. Analysis of the filtrate gave Pd 81 g / L, Pt 7 g / L, Rh 2.1 g / L, Ru 2.4 g / L and Au 3.8 g / L. 6.1 g of hydroxylamine hydrochloride became the solution added as a reducing agent and the mixture was reacted at 60 ° C for 1 hour. Subsequently was chilled and re-analyzed the precious metals in the solution no change the solved one Amounts of Pd, Pt, Rh and Ru, however, was the amount of dissolved gold dropped to 0.05 g / L, indicating that Au is selectively reduced has been.

Comparative experiment 7

When Example 15 was repeated and hydrazine was used as the reducing agent, the Pd and Pt were reduced together with Au, which means that Au is not separated from the solution could.

industrial usability

The separation process according to the invention allows the separation of metals, including the platinum group elements, Pt, Rh, Ir and Ru, as well as selenium, tellurium, gold, silver and copper and the like, for example, contained in the insoluble residue by-product that are in the electrolyte during the copper electrolysis stage of a copper refining and refining process, and the recovery in a simple, effective way at low Costs.

Summary

aim The invention is to provide a separation process that the effective separation of selenium, tellurium and platinum group elements from a selenium / tellurium and containing elements of the platinum group Material allows. In order to make this possible, The invention provides a separation process for elements of the platinum group provided, comprising: a step (A) for treating a Selenium / tellurium and platinum group elements with alkali, a stage (B) for leaching of selenium / tellurium, and a Stage (C) for separating the platinum group element-containing leaching residue and the selenium / tellurium lye.

Claims (29)

Process for the separation of platinum group elements, full: a step (A) for the treatment of a selenium / tellurium and platinum group containing materials with alkali, a Stage (B) for the leaching of selenium / tellurium, and a stage (C) for separating a platinum group element containing leach residue and a selenium / tellurium lye. A separation process according to claim 1, wherein the Stage (A) for the treatment of a selenium / tellurium and platinum group elements containing material with alkali is a step in which a flux, the a mixture of sodium hydroxide and sodium nitrate, to which Selenium / tellurium and platinum group elements together and the resulting mixture by heating to a temperature exceeds the melting point of the melting agent, is melted, the Stage (B) for leaching of selenium / tellurium a stage for leaching an obtained melt with water and the stage (C) for separating the leaching residue containing the elements of the platinum group and the selenium / tellurium leach a stage for performing a solid-liquid separation is using water as a leaching agent, causing the Mixture in a liquid Fraction containing sodium selenite and one residue, of the platinum group elements is separated. A separation process according to claim 2, wherein a molar ratio between sodium hydroxide and sodium nitrate in the range of 75:25 to 85:15 is used. A separation process according to claim 2, wherein the hydrogen peroxide and hydrochloric acid to the residue, contains the elements of the platinum group, be added to the elements to solve the platinum group. A separation process according to claim 2, wherein the selenium / tellurium and platinum group elements, an extraction residue a process precipitation is that after a solvent extraction remains that has been applied to gold from a hydrogen chloride solution to be separated from a decuperated sludge. A separation process according to claim 2, wherein the selenium / tellurium and platinum group-containing material comprises a distillation residue obtained by converting a decuperated sludge in a slurry by addition of hydrochloric acid and hydrogen peroxide, Filtering the slurry, a separation into a leaching residue, the primary silver contains and a lye, the gold, elements of the platinum group, selenium and tellurium contains what to effect the liquid characteristics the liquor are adjusted and then a solvent extraction for separation carried out by gold from the lye, Sulfur dioxide is added to the post-extraction fluid, to selenium and then Tellurium sequentially to reduce and precipitate, and then the precipitated Material containing elements of the platinum group and selenium, for example Concentrating the elements of the platinum group is heated while distilling and selenium is separated. A separation process according to claim 1, wherein the step (A) for the treatment of a selenium / tellurium and platinum group elements containing material with alkali and the stage (B) for leaching of selenium / tellurium are carried out simultaneously as an alkali leaching process, containing selenium / tellurium and platinum group elements Material is leached with alkali at high temperature, causing Move selenium / tellurium into an alkaline liquid and then a Solid-liquid separation is carried out to make the resulting mixture into a solid fraction, the elements contains the platinum group and a liquid one Fraction containing selenium / tellurium to separate. A separation process according to claim 7, wherein hydrochloric acid and an oxidizing agent is added to a separated solid fraction, the at the solid-liquid separation is generated, whereby the elements of the platinum group are dissolved. A separation process according to claim 7, wherein the selenium / tellurium and platinum group-containing material with alkali leached high temperature, causing tellurium in the alkaline liquid migrates with selenium, creating a separation from the elements of Platinum group done. A separation process according to claim 7, wherein the selenium / tellurium and platinum group-containing material using an alkali concentration of at least 1 mol / L at a temperature of at least 60 ° C is leached out. A separation process according to claim 7, wherein hydrochloric acid and either hydrogen peroxide or chlorine gas to the solid fraction from the solid-liquid separation, which is obtained after leaching with alkali is added, whereby the elements of the platinum group are dissolved. A separation method according to claim 7, wherein the elements platinum group one or more of rhodium, ruthenium, palladium and platinum. A separation process according to claim 7, wherein the selenium / tellurium and platinum group-containing material is a process precipitate extraction residue is that after solvent extraction remaining for separation of gold from a hydrogen chloride solution from a decuperated sludge was used. A separation process according to claim 7, wherein the selenium / tellurium and elements containing the platinum group containing a filtered precipitation by converting a decomposed sludge into a slurry Addition of hydrochloric acid and hydrogen peroxide, filtering the slurry to a separation in a leaching residue, the primary Contains silver and a lye, the gold, platinum group elements, selenium, and tellurium contains on what the liquid characteristics the liquor are adjusted and then a solvent extraction for separation made of gold from the liquor where sulfur dioxide is added to the post-extraction liquid, to precipitate either selenium / tellurium and subsequently the precipitate a solid-liquid separation is subjected. A separation method according to claim 7, comprising: one Alkaline melting process (i), which is a step of adding a Melting agent containing a mixture of sodium hydroxide and sodium nitrate includes, to a residue from a distillation treatment of a selenium / tellurium and elements the platinum group-containing material and then heating a temperature exceeding the melting temperature (eutectic) of the mixture, which solved the selenium / tellurium is carried out as stage (A) the alkali treatment, a step for carrying out the leaching with water as stage (B) for leaching selenium / tellurium and further one stage (C) for separating the platinum group element-containing leach residue and the selenium / tellurium lye comprises, and an alkali leaching process (ii) comprising a stage for leaching a selenium / tellurium and Elements of the platinum group-containing material with alkali high temperature as the step (A) for carrying out the alkali treatment and the selenium / tellurium leaching step (B) and then the Step (C) comprises separating the platinum group-containing elements leach residue and the selenium / tellurium lye. A separation method according to claim 15, wherein a Selenium / tellurium and platinum group containing solution of Undergoes reduction treatment and a by undergoing a part of the resulting reducing slag of a distillation treatment generated precipitate then one Subjected to alkali fusion treatment, wherein remaining reduction precipitation of a Alkali leaching treatment is subjected. A separation process according to claim 15, wherein sulfur dioxide gas into a post-gold extraction fluid a precious metal recovery system for electrolysis sludge from copper to introduce a reduction treatment and a residue, the one by the selenium that fails first one Distillation is obtained to separate high-purity selenium, subjected to alkali smelting treatment, whereas tellurium, that next fails, is subjected to alkali leaching treatment. A separation method according to claim 15, wherein a Lye, which is the watery Lye, which in the aqueous Leaching of the alkali melt process is obtained, the alkali leaching is returned and subjected to alkali leaching together with a material which contains selenium / tellurium and platinum group elements. A separation method according to claim 15, wherein a Lye obtained in the alkali leaching process by addition of sulfuric acid or hydrochloric acid is neutralized, whereby selenium / tellurium are precipitated. The separation process of claim 15, wherein hydrochloric acid is added to a Leaching residue, the in the process of leaching with alkali and the alkali fusion process is added in the presence of an oxidizing agent, whereby the elements of the platinum group are dissolved. A separation process according to claim 1, wherein a selenium / tellurium mixture is obtained is from the selenium / tellurium leach and the resulting selenium / tellurium mixture subsequently is introduced in a copper smelting and refining process, to form an alloy of selenium and tellurium with copper and the alloy is subjected to a copper electrolysis to electrolytic To win copper, with selenium and tellurium in the mud of copper electrolysis be enriched, and the sludge of the copper electrolysis then a oxidative leaching with sulfuric acid is subjected to tellurium to dissolve in a brine and to separate from the selenium in a leaching residue. A separation process according to claim 7, wherein a selenium / tellurium mixture is obtained is by addition of sulfuric acid or hydrochloric acid to a selenium / tellurium lye used in the alkaline leaching process which neutralizes the liquor and the selenium / tellurium mixture precipitated and the resulting selenium / tellurium mixture subsequently in A copper refining process is introduced to make an alloy of selenium and tellurium with copper to form and alloy one Copper electrolysis subjected to the extraction of electrolytic copper Selenium and tellurium in the sludge of copper electrolysis be enriched and the sludge of copper electrolysis then a oxidative leaching with sulfuric acid is subjected to tellurium to dissolve in a brine and to separate from the selenium in a leaching residue. A separation process according to claim 15, wherein a selenium / tellurium mixture is obtained by adding a selenium / tellurium lye, which in the alkali fusion to a selenium / tellurium and platinum group elements containing material used in the alkali leaching process will, then leaching with alkali and then sulfuric acid or Hydrochloric acid added to the resulting liquor to neutralize the liquor and the selenium / tellurium mixture precipitate and the resulting selenium / tellurium mixture is subsequently transformed into a copper-melted and refining procedures is used to form an alloy of selenium and tellurium with copper, the alloy of a copper electrolysis for the production of electrolytic Copper is subjected to selenium and tellurium in the sludge of the copper electrolysis be enriched and the sludge of copper electrolysis then an oxidizing Leaching with sulfuric acid is subjected to dissolve tellurium in a brine and from the selenium in one leach separate. A separation process according to claim 21, wherein the selenium / tellurium and platinum group-containing material has a reduction residue that was generated by introducing sulfur dioxide gas into a post-gold extraction fluid and performing a reduction treatment. Separation method according to claim 21, in which on the leaching of tellurium by oxidative leaching of the copper electrolysis sludge with sulfuric acid the resulting liquor is contacted with metallic copper which produces copper telluride which is subsequently recovered becomes. A separation process according to claim 1, wherein hydrochloric acid is added to the Elements of the platinum group containing leach residue in the presence of a Oxidant added is carried out, a solid-liquid separation is performed and hydroxylamine hydrochloride subsequently to the filtered elements the platinum group containing solution is added, to selectively reduce and precipitate gold. A separation method according to claim 26, wherein a Alkali treatment of selenium / tellurium and platinum group elements containing material is carried out at high temperature. A separation process according to claim 2, wherein hydrochloric acid is added to the Platinum group-containing residue in the presence of a Oxidant added is, a solid-liquid separation is performed and hydroxylamine hydrochloride subsequently to the resulting is added to filtered elements of the platinum group-containing solution, to selectively reduce and precipitate gold. A separation method according to claim 26, wherein a post-gold extraction liquid of an noble metal recovery system from copper electrolysis sludge is used as a selenium / tellurium and platinum group-containing material, and sulfur dioxide gas is introduced into the post-gold extraction liquid to effect a reduction treatment and a distillate residue obtained by subjecting selenium, which first precipitates, to a distillation to separate high-purity selenium, is subjected to alkali smelting treatment to separate a residue containing platinum group elements, whereas tellurium is obtained by further introducing sulfur dioxide gas is precipitated into the post-gold extraction liquid, subjected to alkali leaching treatment to form a residue containing platinum group elements, and the residues containing platinum group elements are subsequently combined and used.